This application claims the priority of German Patent Applications Serial No. 199 56 515.5, filed Nov. 24, 1999; and No. 199 56 517.1, filed Nov. 24, 1999; and of Swiss Patent Application Serial No. CH 2000 2055/00, filed Oct. 20, 2000, the subject matter of which is incorporated herein by reference.
The present invention relates to a device for carrying out ophthalmologic surgical procedures, in particular a device for improving drainage of the aqueous humor in an eye, wherein the secreted aqueous humor in the region of the iridocorneal angle of the anterior chamber is conducted via the trabecular meshwork into the Schlemm""s canal and from there through the natural channel system.
The functional capacity of an eye depends on the intraocular pressure (IOP) and requires that the influx and outflow of the aqueous humor (humor aqueous) which circulates between the posterior and the anterior chamber and thereby continually regenerates, is at an equilibrium and natural drainage of the aqueous humor is realized by the aqueous humor flowing at the iridocorneal angle (angulus iridocornealis) via the trabecular meshwork (trabeculum corneasclerale) into the Schlemm""s canal and from there via the natural channel system comprising collecting canaliculi and aqueous humor veins.
When changes in the trabecular meshwork occur due to disease or injury, drainage of the aqueous humor is often diminished resulting in a rise of pressure in the eye commonly known as the disease glaucoma that oftentimes leads to visual impairment that can lead to blindness.
From EP-A 0 550 791 a device is known for treatment of the trabecular meshwork concerning changes that lead to obstruction of the aqueous humor drainage induced by diseasexe2x80x94and injury. The device is for injecting a suitable medium into Schlemm""s canal, which has been partially exposed by cutting open the sclera and folding it upwards. Through this procedure, the venous network of the trabecular meshwork is being stretched and opened at several points effecting a pressure compensation that permits to restore the natural drainage of the aqueous humor by way of the openings, and whereby occlusion of the opening walls is substantially prevented when the walls of the opening are wetted (layered) with the highly viscous medium.
The device and method described in the afore-mentioned printed reference which is directed to the hydraulic stretching of the Schlemm""s canal and the resultant bursting of the trabecular meshwork while proven useful, has in practice however shown to be not entirely successful, in particular, opening or stretching of the trabecular meshwork by hydraulic means is unsatisfactory or not realizable at all where due to disease, changes in the trabecular meshwork in the form of clogs and/or occlusions from the trabecular meshwork growing together, have occurred.
It is thus an object of the present invention to provide an improved device for improving the drainage of the aqueous humor within the eye of a living being, obviating the afore-stated drawbacks. In particular, it is an object of the present invention to provide an improved device for carrying out microsurgery, in particular, for cases where the trabecular meshwork is extremely clogged or has grown together, ophthalmologic surgery can be carried out by which the regulation of the intra-ocular circulation of the aqueous humor may be reactivated and based thereon substantially natural drainage via the trabecular meshwork into the Schlemm""s canal is realized.
This object and others which will become apparent hereinafter, are attained in accordance with the present invention by providing a tube-shaped probe for positioning in the anterior chamber in the direction of the trabecular meshwork which is operatively connected to an endoscope. Axially oriented within the probe is at least one tube-shaped working channel and a tube-shaped optical channel comprising at least one optical element for focusing on a viewing field and for transmitting images from a viewing field. An adjustable microsurgical tool which may be driven manually or by electric motor is disposed within the working channel in axial direction relative to the distal end of the tube-shaped probe. By means of the microsurgical tool at least one passageway can be made in the tissue of the trabecular meshwork such that a connection from the anterior chamber to Schlemm""s canal is realized and to thereby provide drainage of the aqueous humor via the trabecular meshwork into the Schlemm""s canal.